This invention relates to a method of removing oxygen from a gas containing an unsaturated hydrocarbon, and more particularly, to a method for removing oxygen selectively by hydrogenation from a gas containing an unsaturated hydrocarbon, particularly an olefin such as ethylene and propylene.
The oxygen existing as impure matter in a gas containing an unsaturated hydrocarbon must be removed, since it is likely to bring about a number of problems during the handling of the gas, or the recovery of the hydrocarbon therefrom. Accordingly, a number of methods have heretofore been proposed for removing oxygen from a gas containing an unsaturated hydrocarbon.
The prior methods of removing oxygen from olefins include, for example, a method which removes oxygen selectively by adsorption by contacting the gas with an alkali metal amide in ammonia (Japanese Patent Publication No. 3860/1962), or with a resin containing copper as obtained by reducing a high molecular complex compound composed of a high molecular compound and a copper salt (Japanese Patent Application Laid-Open Specification No. 148684/1976); and a method which removes oxygen by hydrogenation, while controlling the hydrogenation of the olefin, by contacting the gas with a molybdenum sulfide catalyst on .alpha.-alumina in the presence of hydrogen (Japanese Patent Publication No. 25241/1974), with a copper catalyst in the presence of hydrogen (Japanese Patent Publication No. 25241/1974), with an activated nickel catalyst in the presence of hydrogen (Japanese Patent Application Laid-Open Specification No. 149207/1976), or with a catalyst composed of a metal of the platinum group, while a sulfur compound is being added thereinto, in the presence of hydrogen (U.S. Pat. No. 3,480,384).
The known methods based on adsorption require the regeneration of the adsorbent, while those which are based on hydrogenation involve difficulty in the selective hydrogenation of oxygen alone, and disadvantageously bring about considerable loss of the olefin by hydrogenation.
Applicants have developed a method for removing oxygen selectively by hydrogenation from a gas containing an olefin and oxygen, without involving any hydrogenation of the olefin.